The invention refers to a lift bed according to the preambles of Patent claims 1 and 6.
From EP-B1-0 418 415 a suspended bed is known with a bed frame which can be adjusted in height and a lifting mechanism for moving the bed frame in the vertical direction. The suspended bed includes a vertically running guiding device mounted on the wall on which the bed frame is supported with one end being able to move in the vertical direction. The lifting device is provided with a self-locking drive and is formed and arranged such that it acts on the bed frame at the mentioned end.
The lifting device comprises at least one electric motor for driving lifting spindles arranged to be self-locking, whereby a crank handle is provided for emergency operation. The handle can be coupled with the lifting spindles, driving them when the crank is rotated.
Furthermore, EP-B1-0 418 415 describes an overload protection device with the aid of which deformation of the bed frame and of the guiding device is prevented when a certain load on the bed frame is exceeded.
The suspended bed described in EP-B1-0 418 415 is very space-saving and safe in operation. In particular, for the case where the lifting device is arranged in the region of the guiding device, practically no living area is taken up when the suspended bed is lifted below the room ceiling. Furthermore, the self-locking drive enables the suspended bed to be supported in any vertical position in an operationally safe manner, free of oscillations.
A disadvantage of the suspended bed according to EP-B1-0 418 415 is however that release of the overload protection device may lead to the injury of a suspended-bed user and, in particular, intensive usage of the suspended bed leads to material fatigue of this overload protection device, which can lead to unprompted release of the overload protection device.
Starting from the known prior art, the object of the invention is a lift bed which exhibits improved safety devices.
This object is realized based on the preambles in Patent claims 1 and 6 with their characterizing features.
In particular this object is realized by a lift bed with a bed frame carried on at least two carriages, whereby each carriage is supported movably on a guide rail arranged vertically for moving the bed frame in the vertical direction and whereby each carriage consists of two parts which are supported in a mutually tiltable manner via a horizontal axle running parallel to the bed-frame width. The two carriage parts of each carriage are joined by an adjustment device clamping them together so that the bed frame mounted on the first carriage part is adjustable in the horizontal position. The adjustment device exhibits an overload device which gives way on reaching a predefined limit load and releases the connection and whereby also an end-stop is provided which holds the bed frame in a slightly angled position after release of the connection.
This invention is based on the knowledge that the stated lift bed is very easy to operate and satisfies high safety requirements.
The further development according to claim 2 has the advantage that the overload protection is a shearing pin which fractures when the specified limit load is exceeded.
The further development according to claim 3 has the advantage that the end-stop is a trapping pin.
The further development according to claim 4 has the advantage that the adjustment device is a screw which is inserted into a suitable threaded hole in the second carriage part and penetrates a hole provided in the first carriage part and that the shearing pin is arranged in a hole provided in the screw and contacts the side of the first carriage part for adjustment on the side facing the bed frame.
The further development according to claim 5 has the advantage that the screw has a head section which is formed as an end-stop.
Furthermore, this object is realized by a lift bed with a bed frame supported by at least two carriages, whereby each carriage is supported movably on an associated vertical guide rail, in the region of the carriages a pulling device is arranged on each one and the pulling devices can be synchronously operated via a common operating device to move the bed frame in height without tilting to the side, whereby the carriages on the guide rails feature side guides which lead to jamming with the sidewards tilting of the bed frame due to uneven weight distribution.
The further development according to claim 7 has the advantage that the guides are each formed as a plastic block.
The further development according to claim 8 has the advantage that the guides each exhibit a coefficient of friction which is specified such that when the bed frame tilts, friction occurring between the relevant guide rail and the corresponding guide leads to jamming.
The further development according to claim 9 has the advantage that the value of the coefficient of friction is 0.35.
The further development according to claim 10 has the advantage that the guides are each formed from metal and move with a play of less than 3 mm on the corresponding guide rail.
The further development according to claim 11 has the advantage that each guide rail is toothed on the side facing the corresponding guide and locking of the relevant guide in a corresponding tooth system leads to jamming when the bed frame tilts.